Opaquing agents for the production of white enamels.



i Parana cannon.

IG-NAZ KREIDL, 01E VIENNA, AUSTRIA-HUNGARY.

'OPAQUING- AGENTS FOR THE :ERODUCTION OF WHITE ENAMELS.

No Drawing.

To all whom it may concern:

Be it known that I, IGNAZ KREIDL, a subject of the Emperor of Austria-Hungary, residing in Vienna, Austria-Hungary, have invented certain new and useful Improved Opaquing Agents for the Production of White Enamels, of which the following is a specification.

Thisinvention has for its object to provideimproved opaquing agents for the pro duction of white enamel more especially zirconium enamels and an improved process for the manufacture of such opaquing agents.

Zirconium compounds,tin compounds, t1- tanium compounds and aluminium compounds have already been proposed for use as opaquing agents for white enamel. It has also been proposed to start from the alkali compounds of the metallic oxids for the manufacture of such opaquing agents, and to remove the whole or part of the alkali by means of acids. Those processes are more particularly suitable for the manufacture of opaquing agents containing alkali, when it I is desired that the opaquing agents shall be obtained combined with a portion of the alkali, that is to say, where the alkali is to be removed only in part.

For the purpose of manufacturing such opaquing agents and more especially opaquing agents free from alkali, there may be used in addition to the alkali compounds, also the acid compounds or the salts of those metallic oxids which are suitable for opaquing purposes. In these cases the acid is removed for instance by means of alkali. 4

When using acid compounds or non-heat refractory i. e. volatile, salts, for instance sulfates, nitrates, salts of organic acids and the like for the manufacturing of the opaquing agents free from alkali the acid may be eliminated directly by heating to a glow heat.

It has been observed in the manufacture of opaquing agents according to the hereinbefore mentioned processes, that the opaquing effect is not so good when the salts Specification of Letters Patent.

Patented Aug. 1L7, 11915.

Application filed September 4, 1913. Serial No. 788,112.

the products which are to be used as opaquing agents are kept in a resistant state by the presence of the saltsor of the acid.

The most favorable proportion of acid or salts differs for each acid, but can be readily determined empirically. The said proportion is however limited in the upward direction, because a too great proportion of acid or salts causes the opaquing agent to lose in opaquing power. When for instance an alkaline zirconium compound, such as a zirconate, is used for the manufacture of the opaquing agent, then according to this invention, the combined alkali is removed at at least in part by means of an acid, preferably a weak acid. The alkali salt thus formed is removed by subsequent-washing out only to the extent as to leave behind such a quantity of thesaid alkali salt which (as found by experiment) will produce a favorable efi'ect. These experiments are easily made, because for this purpose it is merely necessary to testthe opaquing agent as to its covering power for various percentages of salt. When once the most favorable percentage has been ascertained, it is an easy matter to determine by chemical means the stage at WhlCl'J. the washing out operation must be stopped to retain the said ascertained per centage of salt.

In the manufacture of the improved opaquing agents from the alkali compounds it is to be understood that in the removal of the alkali by means of acids, acid may also be combined, and then the excess of acid may be removed by heating to incandescence.

If an acid compound or a salt is used for the manufacturing of the opaquing agents the acid is removed at least in part by means of alkali alone or alkali and heating to incandescence, and the washing out of the alkali salt is regulated in the same manner as hereinbefore stated.

In the manufacture of the improved opaquing agents from acid compounds or salts, the washing out operation may be dispensed with, if the acid is eliminateddireotly by heating to incandescence alone. The acid, however, must not be eliminated completely, because the percentage of contained acid has a great influence upon the opaqumg power.

I have discovered that acids or the salts of acids, such as organic acids which have a What is claimed is: a 1. Opaquing agents for manufacturing White enamels comprising highly basic compounds or complexes, certain compounds of Which have opaquing effects, containing a salt or salts of a volatile acid or acids.

2. Opaquing agents for manufacturing White enamels comprising a highly basic zirconium compound containing a salt or salts of a volatile acid or :acids.

3. Opaquing agents for manufacturing White enamels comprising a highly basic compound containing'zirconium oxid and a salt or salts of a volatile acid or acids.

4. Opaquing agents for manufacturing White enamels comprising a zirconium compound containing a salt or salts of an acid which relatively slightly ionizes.

5. An opaquing agent for manufacturing white enamels comprising a compound of a metal Which produces opaquing efiects, containing a small proportion of the radical :of a volatile acid or acids. 7

6. An opaquing agent for manufacturing White enamels comprising a compound of a metal which produces opaquing eifects, containing a small proportion of a radical or radicals *of an acid which are relatively slightly ionized, such as the radical or radicals of organic acid. r

In Witness whereof, I have hereunto signed my name in the presence of two subscribing Witnesses.

DR; IGNAZ KREIDL.

Witnesses HUGO REIK, AUGUST FUGGER. 

